Hair growth problems are wide-spread. In addition to pattern baldness, which may occur in both males and females, hair loss can be induced by drugs, such as chemotherapy drugs, or by chemical or physical damage, such as by certain hair products or styling techniques. Hair loss may also be triggered by systemic diseases, autoimmune conditions, nutritional deficiencies and physical stress, such as during pregnancy, due to surgery, or due to weight loss. It may also be induced by psychological stress.
Available treatments to promote hair growth are limited. For example, minoxidil, while relatively safe, is only moderately effective. The 5-alpha reductase inhibitor finasteride is not indicated for women or children and has negative side effects. The use of certain polypeptides to promote hair growth has been suggested. (See e.g., U.S. Pat. No. 7,335,641, U.S. Pat. No. 7,524,505, U.S. Pat. No. 7,485,618, and U.S. Patent Application No. 2008/0139469.) To date, the only permanent solution to hair loss is hair transplant surgery, which is both expensive and invasive. Thus, there remains a need in the art for additional agents for promoting hair growth. The present disclosure relates to a method of promoting hair growth comprising administering a fibroblast growth factor receptor 3 (FGFR3) extracellular domain (ECD) to a subject in an amount sufficient to promote hair growth.
Fibroblast growth factors (FGFs) and their receptors (FGFRs) are a highly conserved group of proteins with diverse functions. The FGFR family comprises four major types of receptors, FGFR1, FGFR2, FGFR3, and FGFR4. To date, there are 22 known FGFs, each with the capacity to bind one or more FGFRs. See, e.g., Zhang et al, J. Biol. Chem. 281:15, 694-15,700 (2006). Each FGFR binds to several FGFs, and the different FGFRs may differ from each other both in the selection of FGFs to which they bind as well as in the affinity of those interactions.
The FGFRs are transmembrane proteins having an extracellular domain (ECD), a transmembrane domain, and an intracytoplasmic tyrosine kinase domain. Extracellular FGFR activation by FGF ligand binding to an FGFR initiates a cascade of signaling events inside the cell, beginning with oligomerization of the receptor and activation of receptor tyrosine kinase activity. Each of the ECDs contains either two or three immunoglobulin-like (Ig) domains. When there are three Ig domains, they are referred to as D1, D2, and D3 domains. Receptors having two Ig domains typically lack D1. An acidic motif, called the acid box, is located in the linker region between D1 and D2 in the FGFR extracellular domain. The acid box is believed to interact with the heparin binding site in the D2 domain. Structural studies of FGFR-FGF complexes have shown that FGF ligands interact extensively with the D2 domain, the D3 domain, and the linker region connecting the D2 and D3 domains of an FGFR ECD. In FGFR1-3, an alternative splicing event leads to three versions of the D3 domain, also called Ig domain III. The splice variants of this domain are referred to as domain Δ8-10, IIIb and IIIc. Domain III or D3 is encoded by three exons, two of which are alternatively spliced. Distinct splice variants of FGFR3 have been identified in a range of tissues and cancers, such as FGFR3 IIIb, FGFR3 IIIc, and FGFR Δ8-10 (lacking exons encoding the C-terminal half of Ig domain III and the transmembrane domain). See, e.g., Tomlinson et al., Cancer Res. 65: 10,441-10,449 (2005).
In experiments to determine whether an FGFR4 ECD exhibited antitumor activity in a cancer xenograft model, the inventors discovered that an FGFR4 ECD promoted hair growth at the shaved site where the tumor cells were injected. In contrast, an FGFR1 ECD did not promote visible hair growth. In subsequent experiments, both a native FGFR4 ECD fragment fusion molecule and an FGFR4 ECD variant fusion molecule (“ABMut1”) that retained FGFR4 ECD ligand binding activity promoted hair growth when administered systemically in mice. Experiments in which ABMut1 or agarose beads bound to ABMut1 were subcutaneously injected into the flank of shaved mice showed that local delivery of ABMut1 also promoted hair growth. Further experiments demonstrated that systemic delivery of ABMut1 could also induce anagen in hair follicles, specifically elongation of the dermal papilla into the fatty layer of the dermis. The inventors conducted similar studies with a native FGFR3 ECD fragment fusion molecule and discovered that the FGFR3 ECD fragment promoted hair growth when administered systemically in mice. In contrast, an FGFR2 ECD did not promote visible hair growth. Further experiments demonstrated that the FGFR3 ECD fragment fusion molecule could also induce anagen in hair follicles, specifically elongation of the dermal papilla into the fatty layer of the dermis, while the FGFR2 ECD did not have that effect. See Example 6, FIG. 3A and FIG. 3B. Yet further experiments demonstrate that the FGFR3 ECD fragment fusion molecule stimulates hair growth in a dose dependent manner. See Example 7, FIG. 4.
In certain embodiments, the invention provides a method of promoting hair growth comprising administering an FGFR3 ECD to a subject in an amount sufficient to promote hair growth. In certain embodiments, the FGFR3 ECD is a human FGFR3 ECD. In certain embodiments, the FGFR3 ECD is a non-human FGFR3 ECD. In certain embodiments, the FGFR3 ECD is a native FGFR3 ECD. In certain embodiments, the FGFR3 ECD is an FGFR3 ECD variant. In certain embodiments, the FGFR3 ECD is an FGFR3 ECD splice variant. In certain embodiments, the FGFR3 ECD comprises an Ig domain III chosen from Δ8-10, IIIb and IIIc (the FGFR3 ECD is also referred to as FGFR3-Δ8-10 ECD, FGFR3-IIIb ECD, or FGFR3-IIIc ECD). In certain embodiments, the FGFR3 ECD is an FGFR3 ECD fragment. In certain embodiments, the FGFR3 ECD is a native FGFR3 ECD fragment. In certain embodiments, the FGFR3 ECD is a variant of an FGFR3 ECD fragment. In certain embodiments, the FGFR3 ECD is a fragment of an FGFR3 ECD splice variant. In certain embodiments, the FGFR3 ECD is an FGFR3 LCD acidic region mutein. In certain embodiments, the FGFR3 ECD may be engineered to have a decrease in the total number of acidic residues within the D1-D2 linker. In certain embodiments, the FGFR3 ECD is an FGFR3 ECD D1-D2 linker chimera. In certain embodiments, the FGFR3 ECD D1-D2 linker chimera comprises a D1-D2 linker selected from an FGFR1 D1-D2 linker, an FGFR2 D1-D2 linker, and an FGFR4 D1-D2 linker, in place of the FGFR3 D1-D2 linker. In certain embodiments, the FGFR3 ECD is an FGFR3 ECD glycosylation mutant. In certain embodiments, the amino acid sequence of the FGFR3 ECD is at least 80% identical to SEQ ID NO: 4, 5, 6, or 30. In certain embodiments, the amino acid sequence of the FGFR3 ECD is at least 85% identical to SEQ ID NO: 4, 5, 6, or 30. In certain embodiments, the amino acid sequence of the FGFR3 ECD is at least 90% identical to SEQ ID NO: 4, 5, 6, or 30. In certain embodiments, the amino acid sequence of the FGFR3 ECD is at least 95% identical to SEQ ID NO: 4, 5, 6, or 30. In certain embodiments, the amino acid sequence of the FGFR3 ECD is at least 99% identical to SEQ ID NO: 4, 5, 6, or 30. In certain embodiments, the FGFR3 ECD comprises an amino acid sequence chosen from SEQ ID NOs: 4, 5, 6, or 30. In certain embodiments, the FGFR3 ECD comprises an amino acid sequence chosen from SEQ ID NOs: 34 and 36. In certain embodiments, the FGFR3 ECD lacks a signal sequence. In certain embodiments, the FGFR3 ECD comprises a signal sequence. In certain embodiments, the signal sequence is the native signal sequence of FGFR1, FGFR2, FGFR3, or FGFR4 (SEQ ID NOs: 19-22). In certain embodiments, the signal sequence is not an FGFR signal sequence, but from a heterologous protein.
In certain embodiments, the subject is a rodent, simian, human, feline, canine, equine, bovine, porcine, ovine, caprine, mammalian laboratory animal, mammalian farm animal, mammalian sport animal, or mammalian pet. In certain embodiments, the subject is a human. In certain embodiments, the administering is intravenous, subcutaneous, intraperitoneal, topical, or transdermal.
In certain embodiments, the invention provides a method of growing hair comprising administering an FGFR3 ECD fusion molecule to a subject in an amount sufficient to promote hair growth. In certain embodiments, the FGFR3 ECD fusion molecule comprises an FGFR3 ECD polypeptide and a fusion partner. In certain embodiments, the FGFR3 ECD polypeptide is a native FGFR3 ECD. In certain embodiments, the FGFR3 ECD polypeptide is an FGFR3 ECD variant. In certain embodiments, the FGFR3 ECD polypeptide is an FGFR3 ECD splice variant. In certain embodiments, the FGFR3 ECD polypeptide is FGFR3-Δ8-10 ECD, FGFR3-IIIb ECD, or FGFR3-IIIc ECD. In certain embodiments, the FGFR3 ECD polypeptide is an FGFR3 ECD fragment. In certain embodiments, the FGFR3 ECD polypeptide is a native FGFR3 ECD fragment. In certain embodiments, the FGFR3 ECD polypeptide is a variant of an FGFR3 ECD fragment. In certain embodiments, the FGFR3 ECD polypeptide is a fragment of an FGFR3 ECD splice variant. In certain embodiments, the FGFR3 ECD polypeptide is an FGFR3 ECD acidic region mutein. In certain embodiments, the FGFR3 ECD polypeptide may be engineered to have a decrease in the total number of acidic residues within the D1-D2 linker. In certain embodiments, the FGFR3 ECD polypeptide is an FGFR3 ECD D1-D2 linker chimera. In certain embodiments, the FGFR3 ECD D1-D2 linker chimera comprises a D1-D2 linker selected from an FGFR1 D1-D2 linker, an FGFR2 D1-D2 linker, and an FGFR4 D1-D2 linker, in place of the FGFR3 D1-D2 linker. In certain embodiments, the FGFR3 ECD polypeptide is an FGFR3 ECD glycosylation mutant. In certain embodiments, the amino acid sequence of the FGFR3 ECD polypeptide is at least 80% identical to SEQ ID NO: 4, 5, 6, or 30. In certain embodiments, the amino acid sequence of the FGFR3 ECD polypeptide is at least 85% identical to SEQ ID NO: 4, 5, 6, or 30. In certain embodiments, the amino acid sequence of the FGFR3 ECD polypeptide is at least 90% identical to SEQ ID NO: 4, 5, 6, or 30. In certain embodiments, the amino acid sequence of the FGFR3 ECD polypeptide is at least 95% identical to SEQ ID NO: 4, 5, 6, or 30. In certain embodiments, the amino acid sequence of the FGFR3 ECD polypeptide is at least 99% identical to SEQ ID NO: 4, 5, 6, or 30. In certain embodiments, the FGFR3 ECD polypeptide comprises an amino acid sequence chosen from SEQ ID NOs: 4, 5, 6, and 30. In certain embodiments, the FGFR3 ECD polypeptide comprises an amino acid sequence chosen from SEQ ID NOs: 34 and 36. In certain embodiments, the FGFR3 ECD polypeptide lacks a signal sequence. In certain embodiments, the FGFR3 ECD comprises a signal sequence. In certain embodiments, the signal sequence is the native signal sequence of FGFR1, FGFR2, FGFR3, or FGFR4 (SEQ ID NOs: 19-22). In certain embodiments, the signal sequence is not an FGFR signal sequence, but from a heterologous protein.
In certain embodiments, a method of growing hair comprising administering an FGFR3 ECD fusion molecule to a subject in an amount sufficient to promote hair growth is provided, wherein the fusion partner in the FGFR3 ECD fusion molecule is selected from an Fc, albumin, and polyethylene glycol. In certain embodiments, the fusion partner is an Fc. In certain embodiments, the FGFR3 ECD fusion molecule has an amino acid sequence chosen from SEQ ID NOs: 7-10. In certain embodiments, the FGFR3 ECD fusion molecule has an amino acid sequence chosen from SEQ ID NOs: 11-15, 28, 31-33, 35 and 37. In certain embodiments, the FGFR3 ECD fusion molecule has an amino acid sequence chosen from SEQ ID NO.: 9, 10 and 33. In certain embodiments, the FGFR3 ECD fusion molecule lacks a signal sequence. In certain embodiments, the FGFR3 ECD fusion molecule comprises a signal sequence. In certain embodiments, the signal sequence is the native signal sequence of FGFR1, FGFR2, FGFR3, or FGFR4. In certain embodiments, the signal sequence is not an FGFR signal sequence.